While much of the continental United States endured several cold snaps in January 2014, record-breaking warmth gripped Alaska. Spring-like conditions set rivers rising and avalanches tumbling.

This map depicts land surface temperature anomalies in Alaska for January 23–30, 2014. Based on data from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite, the map shows how 2014 temperatures compared to the 2001–2010 average for the same week. Areas with warmer than average temperatures are shown in red; near-normal temperatures are white; and areas that were cooler than the base period are blue. Gray indicates oceans or areas where clouds blocked the satellite from collecting usable data.

A persistent ridge of high pressure off the Pacific Coast fueled the warm spell, shunting warm air and rainstorms to Alaska instead of California, where they normally end up. The last half of January was one of the warmest winter periods in Alaska’s history, with temperatures as much as 40°F (22°C) above normal on some days in the central and western portions of the state, according to Weather Underground’s Christopher Bart. The all-time warmest January temperature ever observed in Alaska was tied on January 27 when the temperature peaked at 62°F (16.7°C) at Port Alsworth. Numerous other locations—including Nome, Denali Park Headquarters, Palmer, Homer, Alyseka, Seward, Talkeetna, and Kotzebue—all set January records.

The combination of heat and rain has caused Alaska’s rivers to swell and brighten with sediment, creating satellite views reminiscent of spring and summer runoff. On January 25, 2014, the Aqua satellite collected this image of sediment flowing into the Gulf of Alaska from numerous rivers along the state’s southeastern coast.

All of the heat, moisture, and melting snow has elevated the risk of avalanches. A series of extremely large avalanches in late January sent snow and debris crashing onto the Richardson Highway, blocking the road and cutting the port town of Valdez off from highway access. The avalanches dumped a mound of snow 100 feet (30 meters) tall and up to 1,500 feet (460 meters) long on the highway.